Flashcards in Outline of the Disease Process Deck (21):
What are the characteristics of cancer cells?
-loss of contact inhibition
-increase in growth factor secretion
-increase in oncogene expression
-loss of tumour suppressor genes
What are the characteristics of a normal cell?
-oncogene expression is rare
-intermittent or co-ordinated growth factor secretion
-presence of tumour suppressor genes
What are the 3 stage of cancer?
What causes initiation?
What causes promotion of cancer?
What causes progression of cancer?
What are some examples of chemical carcinogens?
-soot and tar
-alcohol and smoking
What are some examples of physical carcinogens?
-radon source is mainly buildings
-increased risk by smoking
-ventilation reduced risk
What are some examples of viral carcinogens?
What are growth factors?
-regulate cell growth and function
-bind to cell membrane receptors
-stimulate activation of intracellular signal transduction pathways
Stimulation may be...
-cell carries receptor and secretes growth factor
-cell escapes normal control mechanism
-GFs acting on a cell are produced locally by the cell or its immediate neighbours
What is p53?
-tumour suppressor gene
-most commonly altered gene in human tumours
-normal function is as transcriptional regulator which promotes DNA repair, apoptosis and differentiation
-G1/S checkpoint control gene
What induced p53?
-cascade of limited sequential steps
-involves tumour-host interactions
-survival of the fittest pertains
How does a tumour metastasise?
-Invades through basement membrane
-moves into extracellular matrix/connective tissue/surrounding cells
-invades blood vessels
tumour cells arrested in distant organ
What enzymes are involved in cell adhesion?
What enzymes are involved in ECM?
What is angiogenesis?
the formation of new blood vesssels
Give an example of a growth factor.
VEGF vascular endothelial growth factor
What does the anti-VEGF antibody avastin do?
-prevents interaction with receptors and activation of downstream signally pathways